The

 "The" is called the "definite article". It's the most common word in English. It contrasts with the "indefinite article" A or An, or with Zero Article. You will find a lot about the under the heading articles. It's either a determiner or a conjunction.

Note:
1. We use /ðə/ before consonant sounds: the cat /ðə 'kæt/.
2. We use /ðiː/ before vowel sounds: the eggs /ðiː 'egz/.

1. Determiner

1.1. The form of the

The always has the same form before singular and plural nouns, or before countable and uncountable nouns.

	countable: singular	countable: plural	uncountable
definite	the town	the towns	the dust
indefinite	a town	towns	dust

1.2. The position of the

The goes before a noun*, and also before any adjectives or other words which describe the noun.

the + noun	the + adjective + noun	the + number + noun
the dogs	the young dogs	the four dogs

* The also sometimes goes before adjectives or pronouns without a noun.
Ex:
1. These apples are unripe. Where are the others?
2. The young should help to care for the old.

All, both, and half go before the in the noun phrase:
Ex: all the food, both (the) shoes, half the cake

1.3. The meaning and use of the

We place the before a noun phrase to show that it has definite meaning. This means that the speaker and the hearer share knowledge about exactly what the speaker is talking about.

singular	the X implies "You know which X I mean"
plural	the Xs implies "You know which Xs I mean"

There are several reasons for using the:

1.3.1. We use the when the situation tells us which X /Xs

Ex:
1. "Where's the cat?" "She's under the kitchen table."
(There is only one cat and one kitchen table in the house, so we know which one.)

2. My father left the car in the garage. (of a particular home)

3. Have you visited the castle? (in a particular town)

4. Don't the roses look lovely? (in a particular garden)

1.3.2. We use the when general knowledge tells us which X /Xs

Ex:
1. The earth goes around the sun.
(There is only one earth and one sun, so we know which one.)

Hare are other examples where we use the because there is only one X or group of Xs.
the sea
the sky
the future
the North Pole
the United Nations
the Thai government
the middle class
the Great Wall of China

Note: Similar to this:
1. In the U.K.: the Queen = "the Queen of the U.K."
2. In the U.S.A: the President = "the President of the U.S.A."

1.3.3. We use the when the words after the noun tell us which X /Xs

Ex:
1. She's the president of the Pony Club.

2. The girls sitting over there are my sisters.

3. The bicycle John bought last week has been stolen.

4. I'm studying the history of China.

1.3.4. We use the when what has been said before tells us which X /Xs

Ex:
1. They have a son and two daughters. The son is working as an engineer, but the daughters are still at high school.

(Here, after the son and daughters have been mentioned once, we can use the. This's called "anaphoric reference".

2. It's a fine bicycle, but the brakes don't work.

(Here, we haven't mentioned which brakes, but we have mentioned the bicycle they belong to, so we know which brakes they are.)

1.3.5. We use the before some words which imply that the X is the only one: superlative, ordinals, (the) same, only

Ex:
1. They are all good players, but Jane is the best.

2. When is the first train to Bangkok tomorrow?

3. Sam is the same age as Jany: they're twins.

4. This is the only pair of glasses I have.

1.3.6. We use the in referring to media generally

Ex:
1. We go to the theatre* every month.

2. The freedom of the press is very important.

3. What's on the radio this morning?

* Note that the theatre does not have to mean "a particular theatre". When referring to television we sometimes omit the article.
Ex: on (the) television [see zero article]

1.3.7. Talking about people / animals / things in general

We also sometimes use the in talking about people, animals, or things in general.

Ex:
1. People:

A. They reported the theft to the police.

B. The people who are suffering are the poor, the old, the homeless, and the unemployed.

---

2. Animals:

A. The elephant is the largest animal on land.

---

3. Inventions:

A. Modern society has learned to live with the computer and the mobile phone.

---

4. Musical instruments:

A. Sam's learning to play the violin.

---

Note:
1. We do not use the when describing substances or masses in general.
Ex: Water contains oxygen. (the water, the oxygen)

2. We do not use the whe describing abstractions in general.
Ex: Which do you like best, music or mathematics? (the music, the mathematics)
Be careful to omit the in examples such as these:
(i) We cannot imagine the life a hundred years from now.
(ii) He prefers to teach the American English.
(iii) In the modern society, crime often pays, unfortunately.

3. We do not use the when referring in general to a whole class of things or people (except with nationality words like the Chinese, the Japanese).
Ex: Modern children enjoy computer games. (the children, the games)

2. Conjunction

Form: THE + COMPARATIVE (...) + THE + COMPARATIVE (...)

In this pattern, the is like a conjunction, rather than an article.

Ex:
1. The harder you work, the more successful you will be. (= "As you work harder, you will become more successful.")

2. The more he thought about it, the less he liked it.

Sometimes we omit all words except the + comparative.

Ex:
1. "Can I bring my friends to the party?" "Yes, the more, the better."
(This is the saying which means "the more people there are, the better it is").

2. "I hope I'm not too young for the job." "Not at all. The younger the better."

For the use of the with names, see names and geographical names.

I hope this article helps. If you have any question, please leave a comment below.